[FullyZooked]

I would be ever so greatful if someone could please provide pictures and details as to which screw to set both cold and hot idle speeds on the mikuni.

For future reference for fellow searchers maybe the adjustment location for choke and the setting procedure.

I have searched all over and cannot find any info? I even went and purchased a Haynes manual today that is a POS and has next to no detail regards this .

[FullyZooked]

Surely someone knows the Vitara Carbs?

[atari4x4]

i know nothing

[FullyZooked]

It seems we are all in the same boat. Working on cars no problem but not the carb. Maybe someone has a link to info? Would be a great asset to the site.

[shakes]

carby's are alot like auto electrickery... alot of people think they know what they are talking about, but only know enough to get themselves into trouble

[SuziBlu]

atari4x4 wrote:

:oops: i know nothing

aaaahahahahaaaa, ya finally come clean, woohoooo yess yess oh yesss, er, ahem, that is to say, sorry, cant help either.

[buzbox]

I don't have the workshop manual with me at the moment, But I'll try to get some info out of it which may or may not help you out. I'll post it up tonight.

But in the meantime, youtube is your friend. Sure they're for Holley carb's but pretty much same principle applies.

http://www.youtube.com/watch?v=TCurlDWBr9k

http://www.youtube.com/watch?v=6vKlAnKdcB4

[FullyZooked]

That's why I want to keep this top of mind. Surely someone with Vitara Mikuni experience will drop by and bless us with their knowledge.

[FullyZooked]

If you could please post the info tonight that would be great buzbox.

I have no problem tuning a Carbs air/fuel ratios but need to know where all specific screws are located i.e hot and cold idle screws, idle mixture screw.

Thanks again.

[SuziBlu]

Im sitting doing nothing, so I thought I would have a search of the web for ya, nothing found for motor car engines, only for motor bike engines, shitloads of info for them, tons, but nothing for cars, sorry.

[FullyZooked]

Just remember Suziblu we are chasing this specific details on the Mikuni found on G16A's.

I have faith in thy' fellow auszookers!

[SuziBlu]

The only reference I found was in a suzi forum from 2007, israily bloke asked, answer was a smart arse one.

Parently the last of them was 1988, that is all I could find, no other reference.

[matty_wall]

Ive been having trouble with my vitara carby as well.

Idle up not working. Running rich. Cant hold idle when slowing down, resulting in staling sometimes.

I'm gonna spend the weekend on mine, see if i can contribute some tech that can go into the good tech section.

[FullyZooked]

Ill give you a small piece of the experience I have had.

If standing in front of the car, the right back of the carb you will see 3 screws, Two large phillips head screws and one small flat head screw. I have found the small flat head screw increses both cold idle and hot idle? WTF.

Thats about as much as I know. I will look forward to your findings.

[FullyZooked]

How'd you go Matty? Any luck?

C'mon Royce your the master of all things tech. Any ideas?

[losfer]

heres a picture , the red lines point to the arm and the screw for the ac adjustment so you cant mix it up with the others .

the cold idle screw you have to open the throttle up to access it.

HTH

[Jester]

thanks, ive printed that out for myself also

[FullyZooked]

You my friend are a champ!

[FullyZooked]

Shit I've been turning 11 on that diagram to increse idle. Looks to be idle mixture, that makes sense why it raises both cold and hot idle. I don't suppose you know the stock value for this screw? 1-1/2 out?

[FullyZooked]

Is it just me or do you have the hot and cold idle back to front? Would the operating temp idle be on the butterfly arm? Otherwise if adjusted for cold idle the high rpm would stay even when hot?

[royce]

FullyZooked wrote:

Is it just me or do you have the hot and cold idle back to front? Would the operating temp idle be on the butterfly arm? Otherwise if adjusted for cold idle the high rpm would stay even when hot?

No, they are correct, the cold idle speed screw acts against a cam that moves with the choke to reduce the idle speed once hot

the hot idle screw acts against the throttle linkage as a stopper

the idle mixture I usually go with at temp and idling, timing correct etc, wind it out till the idle speed is as high as it will get then starts to drop and go in a little bit, its not emissions correct but best youll get at home

[FullyZooked]

Right so to get this straight, confused now.

The screw in the throttle linkage where the cable runs is the cold idle?

The long screw out the side of the carb is to adjust idle when engine is at running temp?

I can't get my head around how that could be right.

[losfer]

well royce told you , the one on the the throttle linkage rests against a cam , as the car warms up , the cam is moved away by a thermal wax element . as the cam moves away the idle decreases until the throttle linkage rests upon the hot idle screw , stopping it from going any further.

dont think about it and you wont get confused , just adjust the fucking thing !

as for the mixture screw , screw it in until you can feel the engine start to die and run rough , then wind it out until it just starts to sound sweet again , then another 1/2 turn for good measure

[FullyZooked]

Just got back from the shed and yes I now understand.

Had a good close squizz with the worklight and can see how it all works. The carb was governed only by the choke for both hot and cold idles. Turning the hot idle screw 2 turns in or out had no affect.

Once I lowered the cold idle I was then able to set the correct idle RPM using the hot idle screw. Awesome.

Not only that the bottom end is so much more responsive now! Previously the choke always being partially on must have richened it somewhat.

Thanks for the help.

[mavmitchell]

Hi,

Not sure if anyone is still looking for solutions to rich idle on G16B with Mikuni.

I just spent 3 days chasing this prob down on my Maruti with this engine.

I found the secondary butterfly was not closing fully at idle, and it was breating through the secondary.

I removed the secondary shaft and cleaned it with wet and dry.
Its now not sticky and closes fully every time.

Runs like new...

[xrwardy]

Hi,

I also have been searching for info on this carb and bingo i found this

only trouble is that i can't see the picture, where's it gone?

any chance of posting it back up please?

thanks.

[xrwardy]

ah, i can see the picture now

what does ac idle up adjust do? or what does ac stand for?

thanks again.

[HarryHoudini]

AC in an Automotive sense is Air Conditioning.

[fritter]

It increases the idle rpm when the AC is on to compensate for the increased load
on the alternator.

Cheers

[xrwardy]

thanks guys,

mine aint got ac, we don't have use for one in the uk